This invention relates to bulk storage tanks and more specifically, to safety devices to prevent unauthorized access to, and withdrawal of product from, a bulk chemical tank, such as an anhydrous ammonia nurse tank.
In recent years the illegal production of methamphetamine has become a major problem in the United States. Anhydrous ammonia is an ingredient in the manufacture of illegal methamphetamine. The United States government also has identified Anhydrous ammonia as a compound that terrorists might utilize for attacks on this country.
Anhydrous ammonia is used legitimately in agriculture as a source of nitrogen, a plant nutrient, for example in the production of grain and forage crops throughout the world. Anhydrous ammonia generally is transported and stored as a pressurized liquid. Most commonly, in agricultural use, anhydrous ammonia is transported to farm fields in nurse tanks. Various sprayers, hoses, or the like are attached to a liquid withdrawal valve to allow withdrawal or application of the product. Between uses, these tanks typically are stored at the chemical supplier's location or on the farm or in the fields. In recent years there has been a significant rise in tampering with the nurse tanks and theft of the anhydrous ammonia for use in production of illegal methamphetamine. Generally, the thief gains access to the liquid withdrawal valve and removes the liquid anhydrous ammonia from the tank.
It would beneficial, therefore, to have an apparatus that prevents the unauthorized access to the nurse tank valve and the subsequent removal of anhydrous ammonia for illegal purposes.